A conventional way to make bicycle frames by composed material such as carbon-fiber is first make the bicycle parts such as the head tube, the top tube, the down tube and the seat tube individually. These parts are made by carbon-fiber sheets which are overlapped with each other to form the desired shape. These carbon-fiber sheets are then heated under a certain pressure to become solid pieces. The individual parts are then connected with each other by using connection members to connect two or three parts together. However, the individual parts are stiff so that they are not able to be deformed when needed so that a gap between two respective ends to be connected could be too wide to well support the load applied to the two parts. Although these gaps are covered by the connection members, potential risks still exist. After a period of time of use, the connection members tend to be broken. Besides, the conventional method limits the bicycle frames to have few fixed shapes.
The present invention intends to provide a method for making bicycle frames by composite material and the shapes of the frames are set when the parts are in deformable and flexible status.